I really enjoy the game and I have to agree with what Daystar has said. Though one of the biggest flaws I see in STO is the level cap. For example in WoW they can keep expanding the level cap with each expansion they come out with. With the new expansion for WoW coming out the end of 2010 the level cap will increase to 90. With STO you can reach Rear Admiral Lower Half comparatively quickly and even with expansions that will come out they can only go so high as Fleet Admiral. One of the rewards for gaining experience is making it to the next level. Once they max out the Starfleet and Klingon ranks, that is it. No more rewards for gaining experience. IMO what they should have done is make it harder to get to the next rank but you will still level up. (ex you have Lt1, Lt2, Lt3, ect.) Another thing to do would be to add a lot more ships so say when you reach LT5 you can get a new ship and at Lt10 you can get another one, just make it harder to get to those ranks. This would extend the life of your Starfleet character, because once you reach lv cap, you really have no reason to use that character anymore other than to help a fellow fleet mate having trouble with a mission.
There is plenty to do with a level capped character in almost every MMO. It's impossible that you've done ALL the content on your journey to that level, most mmo's let you go back and pick up old missions in some way (Cryptic introduced Ouroboros in CoH, which let you go back to missions you had outlevelled/didn't choose that story path), and was handled quite brilliantly (Still one of the most used systems in that game even still). Increasing the difficulty of gaining levels is a
terrible idea, because the attention span of the average gamer is pathetically low. The only reason Everquest managed it was because the die-hard fanbase of the game sought a tough experience, whereas STO is more built for the casual gamer (As most MMO's are nowadays, unfortunately).
The casual gamer on average gains less entertainment with the fewer rewards and benefits they are awarded per session, if you extended the time it took to level by 2x, by level 10 you'd be requiring like, say, 10-15 missions to hit level 11 with the Cryptic XP formula, which is typically longer than one sitting, and for such a low level is totally not worth it.
Who said they can't get creative with their level cap? If they DID extend it they can always make up new names, Temporal Commander <Name here>. See? Already viable given the setting of STO.
What
I would suggest would be making ships attainable by endgame achievements, to broaden the variety. Wouldn't it be cool to see more than the (HYPOTHETICAL) 3 top tier PVP crafts in groups of 5 just spamming the same broken endgame power? (/HYPOTHETICAL) Though that's a problem that several games suffer from (*COUGHRAGNAROK ONLINE*COUGH*)